The present invention relates to a hand truck and, more specifically, to a hand truck that is convertible into either one of a cart and an inclined cart.
Many devices have been developed over the years to aid people in the movement and transportation of items that otherwise would be too heavy or unwieldy to move. There exists a multitude of powered devices such as cranes, forklifts, hydraulic ramps, etc. that simplify moving. A similar variety of non-powered devices also exist for people to choose from. Non-powered devices, such as pulleys, ropes, clamps, levers and hand trucks, are commonly available to consumers. The ease of use of contemporary hand trucks makes the hand truck an ideal tool for transporting heavy objects and has led to the common use of hand trucks by tremendous numbers of people.
The wide utilization of hand trucks has caused many manufacturers to research improvements in the design of the modem hand truck. Today, industrial quality hand trucks are produced that have frames made of sturdier, tougher materials to simplify transporting appliances and other items that are too large for smaller sized hand trucks. Additionally, hand trucks have been developed that are convertible into a cart or into an inclined cart to simplify the carrying of some objects.
One disadvantage of contemporary hand trucks which are convertible into a cart or into an inclined cart, is the lack of a stable locking structure to secure the hand truck in the desired position. This deficiency can result in the hand truck becoming dislodged from the desired position when the hand truck impacts a bump or other object. Additionally, some hand trucks that are convertible into different configurations use parts or members that are substantially detached depending on the position into which the hand truck is being configured. This increases the difficulty of adjusting the position of a hand truck and requires operators to physically attach part(s) of the hand truck to change the configuration of the hand truck.
The present invention overcomes many of the drawbacks of the contemporary art by providing a hand truck that is convertible into an inclined cart, that is convertible into a cart, that preferably uses dual locking mechanisms to secure the hand truck in a desired configuration, that preferably uses a channel to avoid having members substantially detached from the hand truck to configure the and truck in a desired position, and that smoothly transitions between various possible configurations.
Briefly stated, in one embodiment, the present invention is directed to a hand truck convertible into either one of a cart and an inclined cart including a primary frame having a first pair of wheels rotatably mounted thereon. A secondary frame is pivotally attached to the primary frame and has at least one additional wheel rotatably mounted thereon. The secondary frame is moveable into a position selected from any one of the group consisting of a hand-truck-position, generally parallel to the primary frame, a cart-position, generally perpendicular to the primary frame, and an inclined-cart-position, generally positioned at a predetermined angle with respect to the primary frame. The secondary frame, while in either one of the inclined-cart-position and the cart-position, causing the at least one additional wheel, in combination with the first pair of wheels, to be capable of supporting the primary frame. A connecting member is attached to the secondary frame. A first locking mechanism is attached to the primary frame and detachably secures the secondary frame to the primary frame while the secondary frame is in the hand-truck-position and while the secondary frame is in the inclined-cart-position. A second locking mechanism is attached to the primary frame and detachably secures the connecting member to the primary frame while the secondary frame is in the inclined-cart-position.
The present invention is alternatively directed to a hand truck convertible into either one of a cart and an inclined cart including a primary frame having a first pair of wheels rotatably mounted thereon. A secondary frame is pivotally attached to the primary frame and has at least one additional wheel rotatably mounted thereon. The secondary frame is moveable into a position selected from any one of the group consisting of a hand-truck-position, generally parallel to the frame, a cart-position, generally perpendicular to the primary frame, and an inclined-cart-position, generally positioned at a predetermined angle with respect to the primary frame. The secondary frame, while in either one of the inclined-cart-position and the cart-position, causing the at least one additional wheel, in combination with the first pair of wheels, to be capable of supporting the primary frame. A channel is formed in the primary frame. A connecting member is attached to the secondary frame and is slideably engaged with the channel.